Five people taken to hospital after falling ill due to...

1of2Five people were taken to the hospital on Thursday, Dec. 12, 2019 when an odor emanating from the battery of a charging Toyota Prius parked near a Mountain View robotics company started making people ill, according to the Mountain View Fire Department.Photo: Mountain View Fire Department

2of2Five people were taken to the hospital on Thursday, Dec. 12, 2019 when an odor emanating from the battery of a charging Toyota Prius parked near a Mountain View robotics company started making people ill, according to the Mountain View Fire Department.Photo: Mountain View Fire Department

Five people were taken to the hospital Thursday when they became ill after vapors emanated from an overheated car battery that was being charged in a parking garage in Mountain View, officials said.

Firefighters responded to a 911 call reporting an odor making people sick at Nuro, a robotics company located at 1300 Terra Bella Ave. shortly before 12:45 p.m., according to the Mountain View Fire Department.

Fire officials said they determined that the odor was coming from a Toyota Prius being charged in an “enclosed space” at a nearby address, located at 1340 West Middlefield Road. Fire officials said employees were exposed to unspecified “vapors from an overheated car battery.” Nuro officials said the Prius was charging in a parking garage at the time.

Officials said the incident began Thursday morning, when a Nuro depot manager temporarily evacuated the building after someone first reported the smell to Nuro management at 10:30 a.m.

Related Stories

In a statement to The Chronicle, Nuro officials said, “In an abundance of caution, necessary steps were taken to reduce risk to Nuro personnel” after employees reported an “unpleasant odor” coming from a Prius in Nuro’s parking garage.

After an unknown amount of time, the Nuro employee declared the building “safe for reentry,” fire officials said.

By 12:30 p.m., fire officials said employees starting reporting they were feeling ill to Nuro managers.

“It was determined the odor was coming from the Prius’ battery and the vehicle was unplugged and the battery was removed from the vehicle,” fire officials said in a statement.

Nine Nuro employees — who were working at the Terra Bella Avenue location and the West Middlefield Road location— requested medical evaluations by firefighters.

Five of the patients were taken to a local hospital, and four of the patients declined further medical treatment. Their conditions were unknown on Thursday.

A hazardous materials team with the Fire Department conducted tests and “quickly determined that the building was in fact safe for occupancy.”

Lauren Hernández joined The San Francisco Chronicle in 2018. She covers crime, mayhem and breaking news. Previously, she was a breaking news reporter for the USA TODAY Network’s Statesman Journal in Salem, Oregon. She graduated from San Jose State University in 2015 with a bachelor’s of science in journalism and a minor in philosophy. She is a member of the National Association of Hispanic Journalists. She is also a licensed drone pilot through the Federal Aviation Administration.